1. Field of the Invention
The present invention generally relates to a vacuum cleaner for ordinary household use, and more particularly, to a floor nozzle of the vacuum cleaner.
2. Description of the Prior Art
Japanese Patent Publication No. 59-52548 discloses a floor nozzle of a vacuum cleaner for raking up dust or waste thread on a carpet, a hard floor made of wood or the like, drawing the dust into a dust bag accommodated in a cleaner body.
Japanese Patent Publication No. 52-6036 discloses another floor nozzle for a vacuum cleaner.
These prior art nozzles are shown in FIGS. 1 and 2.
The floor nozzle shown in FIG. 1 is provided with an intake opening 2 formed on a lower side of a nozzle body 1 and a plurality of brushes 3 disposed in front of and behind the intake opening 2 for raking up dust on a floor. The brushes 3 are so held by respective holders 4 as to be adjustable in their vertical positions according to the kind of surface to be cleaned. The nozzle body 1 is supported by a pair of rollers 6 and communicates a suction side of the cleaner body by way of an intake joint 5.
FIG. 2 depicts an attachment nozzle provided with a cylindrical rotor 8 inside and at a central portion of a nozzle body 7 and a pair of guide walls 9 each having a circular internal surface 9a spaced from the rotor 6 at a fixed interval. A great number of inclined short bristles 10 are formed on the entire external surface of the rotor 8 and on the entire internal surfaces of the paired guide walls 9a to rake up dust on a surface to be cleaned. Arrows shown in FIG. 2 indicate intake air flows.
When the vacuum cleaner having the conventional floor nozzle of FIG. 1 is used on a carpet, the brushes 3 are caused to move inwards so as not to be caught by the carpet and not to prevent the cleaner from smoothly moving on the carpet. Because of this, the suction force of the cleaner, even with the slight raking by the brushes 3, can not sufficiently catch fibrous dust, for example, waste thread on the carpet, and therefore, the dust is frequently left on the carpet. Consequently, the vacuum cleaner of this kind can not fully use its ability, and can not keep itself clean, since the waste thread caught by the brushes 3 can not be drawn into the cleaner and is kept caught on the brushes 3.
In the example of FIG. 2, the bristles 10 of the rotor 8 are occasionally caught by the carpet according to the kind of the carpet or due to an unevenness of force imparted by an operator. This imposes an extremely increased force upon the operator in order to operate the nozzle. Accordingly, the operator sometimes feels it hard to control the vacuum cleaner with this attachment nozzle. This attachment nozzle is not serviceable in cleaning the hard floor, since the rotor 8 with the bristles 10 has the disadvantage of poor handling on the hard floor, or hard particles such as sand or the like caught by the bristles 10 sometimes scratch the surface of the floor.